检索结果-南通市图书馆

Journal of Magnesium and Alloys 2024年第7期12卷 2890-2908页

作者： Luyi Han Xiangjian Zhu Dejin Wei Yanan Yu Guangchun Wang key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinanShandong 250061PR China

According to a high-temperature compression test of rare earth magnesium alloy(WE43),a strain-compensated constitutive model of the Arrhenius equation based on Zener-Hollomon parameters was established,and the rheological behaviors were *** model exhibited relatively serious prediction distortion in the low-temperature and high-strain rate parameter interval,and its accuracy was still unsatisfactory even after modification by a correction operator considering the coupling of temperature and strain *** microstructure characterization and statistical analysis showed that a large number of twinning occurred in the parameter intervals with prediction *** occurrence of twinning complicated the local internal stress distribution by drastically changing the crystal orientation and led to significant fluctuations in the macroscopic strain-stress and hardening curves relative to the rheological processes dominated by the dislocation and softening mechanisms,making the logarithm of the strain rate and stress deviate from the linear *** twinning phenomenon was greatly influenced by the temperature and strain ***,the influence mechanism on twinning behavior was analyzed from the perspective of the interaction of dislocation and twinning.

关键词： RE magnesium alloy Hot deformation Zener-Hollomon parameters Arrhenius constitutive model Dislocation Twinning

Large valley-polarized state in single-layer NbX2 (X=S,Se):Theoretical prediction

在线全文

学校读者我要写书评

暂无评论

Nano research 2021年第3期14卷 834-839页

作者： Yanmei Zang Yandong Ma Rui Peng Hao Wang Baibiao Huang Ying Dai School of Physics State Key Laboratory of Crystal MaterialsShandong UniversityShandanan Street 27Jinan250100China

Exploring two-dimensional valleytronic crystals with large valley-polarized state is of considerable importance due to the promising applications in next-generation information related ***,we show first-principles evidence that single-layer NbX_(2)(X=S,Se)is potentially the long-sought two-dimensional valleytronic ***,the valley-polarized state is found to occur spontaneously in single-layer NbX_(2),without needing any external tuning,which arises from their intrinsic magnetic exchange interaction and inversion ***,the strong spin-orbit coupling strength within Nb-d orbitals renders their valley-polarized states being of remarkably large(NbS_(2)∼156 meV/NbSe_(2)∼219 meV),enabling practical utilization of their valley physics *** additional,it is predicted that the valley physics(i.e.,anomalous valley Hall effect)in single-layer NbX_(2) is switchable via applying moderate *** findings make single-layer NbX_(2) tantalizing candidates for realizing high-performance and controllable valleytronic devices.

关键词： valley polarization ferromagnetic anomalous valley Hall effect NbX_(2)(X=S,Se) first-principles

Secure and Trusted Interoperability Scheme of Heterogeneous Blockchains Platform in IoT Networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Communications 2023年第11期20卷 225-241页

作者： Xiao Liu Mingyuan Li Haipeng Peng Shoushan Luo School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

With the rapid development of the Internet of Things(IoT),there is an increasing need for interac-tion between different *** order to improve the level of interconnection,especially the interoper-ability of users/devices between different nodes is very *** the IoT heterogeneous blockchain sce-nario,how to ensure the legitimacy of the chain and how to confirm the identity of cross-chain informa-tion users/devices become the key issues to be solved for blockchain *** this paper,we pro-pose a secure and trusted interoperability mechanism for IoT based on heterogeneous chains to improve the security of blockchain *** this mecha-nism,a primary sidechain architecture supporting au-thentication at both ends of the heterogeneous chain is *** addition,a distributed gateway archi-tecture is proposed for cross-chain authentication and protocol *** security and performance analysis shows that our scheme is feasible and effec-tive in improving the security of cross-chain opera-tions in IoT.

关键词： authentication blockchain Interoperabil-ity heterogeneous chain IoT

Intertwined ferroelectricity and topological state in twodimensional multilayer

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2021年第1期7卷 1569-1574页

作者： Yan Liang Ning Mao Ying Dai Liangzhi Kou Baibiao Huang Yandong Ma School of Physics State Key Laboratory of Crystal MaterialsShandong UniversityShandanan Str.27Jinan 250100People’s Republic of China School of Mechanical Medical and Process EngineeringQueensland University of TechnologyGarden Point CampusBrisbaneQLD 4001Australia

The intertwined ferroelectricity and band topology will enable the non-volatile control of the topological states,which is of importance for nanoelectrics with low energy costing and high response ***,the principle to design such system is unclear and the feasible approach to achieve the coexistence of two parameter orders is ***,we propose a general paradigm to design 2D ferroelectric topological insulators by sliding topological multilayers on the basis of first-principles *** trilayer Bi2Te3 as a model system,we show that in the van der Waals multilayer based 2D topological insulators,the in-plane and out-of-plane ferroelectricity can be induced through a specific interlayer sliding,to enable the coexistence of ferroelectric and topological *** strong coupling of the order parameters renders the topological states sensitive to polarization flip,realizing non-volatile ferroelectric control of topological *** revealed design-guideline and ferroelectric-topological coupling not only are useful for the fundamental research of the coupled ferroelectric and topological physics in 2D lattices,but also enable innovative applications in nanodevices.

关键词： properties topological ferroelectric

Voltage Unbalance Compensation in Distribution Feeders Using Soft Open Points

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2022年第4期10卷 1000-1008页

作者： Rui You Xiaonan Lu College of Electrical Engineering Qingdao UniversityQingdao 266071China College of Engineering Temple UniversityPA 19122USA

Soft open points(SOPs)are power electronic devices that may replace conventional normally-open points in distribution *** can be used for active power flow control,reactive power compensation,fault isolation,and service restoration through network reconfiguration with enhanced operation flexibility and grid *** to unbalanced loading conditions,the voltage unbalance issue,as a common problem in distribution networks,has negative impacts on distribution network *** this paper,a control strategy of voltage unbalance compensation for feeders using SOPs is *** the power flow control,three-phase current is regulated simultaneously to mitigate the unbalanced voltage between neighboring feeders where SOPs are *** voltage unbalance and current unbalance among three phases are compensated with the injection of negative-sequence and zero-sequence current from *** in response to power outages,three-phase voltage of isolated loads is regulated to be balanced by the control of SOPs connected to the feeders under faults,even if the loads are unbalanced.A MATLAB/Simulink model of the IEEE 13-bus test feeder with an SOP across feeder ends is implemented,and experimental tests on a hardware-in-the-loop platform are implemented to validate the effectiveness of the proposed control strategy.

关键词： Distribution network service restoration soft open point(SOP) voltage unbalance compensation

2D spontaneous valley polarization from inversion symmetric single-layer lattices

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2022年第1期8卷 617-623页

作者： Ting Zhang Xilong Xu Baibiao Huang Ying Dai Yandong Ma School of Physics State Key Laboratory of Crystal MaterialsShandong UniversityShandanan Street 27Jinan250100China

2D spontaneous valley polarization attracts great interest both for its fundamental physics and for its potential applications in advanced information technology,but it can only be obtained from inversion asymmetric single-layer crystals,while the possibility to create 2D spontaneous valley polarization from inversion symmetric single-layer lattices remains ***,starting from inversion symmetric single-layer lattices,a general design principle for realizing 2D spontaneous valley polarization based on van der Waals interaction is mapped *** first-principles calculations,we further demonstrate the feasibility of this design principle in a real material of *** remarkably,such design principle exhibits the additional exotic out-of-plane ferroelectricity,which could manifest many distinctive properties,for example,ferroelectricity-valley coupling and magnetoelectric *** explored design-guideline and phenomena are applicable to a vast family of 2D *** work not only opens up a platform for 2D valleytronic research but also promises the fundamental research of coupling physics in 2D lattices.

关键词： materials symmetric lattices

Identification of abnormal conditions in high-dimensional chemical process based on feature selection and deep learning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2020年第7期28卷 1875-1883页

作者： Wende Tian Zijian Liu Lening Li Shifa Zhang Chuankun Li College of Chemical Engineering Qingdao University of Science&TechnologyQingdao 266042China Qingdao NOVAN Electromechanical Technology Qingdao 266100China State key Laboratory of Safety and Control for Chemicals SINOPEC Qingdao Research Institute of Safety EngineeringQingdao 266071China

Identification of abnormal conditions is essential in the chemical *** the rapid development of artificial intelligence technology,deep learning has attracted a lot of attention as a promising fault identification method in chemical process *** the high-dimensional data identification using deep neural networks,problems such as insufficient data and missing data,measurement noise,redundant variables,and high coupling of data are often *** tackle these problems,a feature based deep belief networks(DBN)method is proposed in this ***,a generative adversarial network(GAN)is used to reconstruct the random and non-random missing data of chemical ***,the feature variables are selected by Spearman’s rank correlation coefficient(SRCC)from high-dimensional data to eliminate the noise and redundant variables and,as a consequence,compress data dimension of chemical ***,the feature filtered data is deeply abstracted,learned and tuned by DBN for multi-case fault *** application in the Tennessee Eastman(TE)process demonstrates the fast convergence and high accuracy of this proposal in identifying abnormal conditions for chemical process,compared with the traditional fault identification algorithms.

关键词： Chemical process Deep Belief Networks Fault identification Generative Adversarial Networks Spearman Rank Correlation

Stress Echocardiography for Chronic Coronary Syndrome:Clinical Practice Guidelines(2023)

在线全文

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2024年第5期21卷 475-505页

作者： Peng-Fei ZHANG Jia-Wei TIAN Tian-Gang ZHU Jue-Fei WU Xiao-Ping LENG Yi WANG Meng-Meng LI Xin-Hao LI Qian-Qian WANG Xiao-Peng FENG Jia-Yan LV Li-Xue YIN Yun ZHANG Mei ZHANG Chinese Society of Echocardiography,Superficial Tissue and Vascular Group of Chinese Society of Ultrasound in Medicine,Ultrasound Professional Committee of Chinese Medicine Education Association State key Laboratory for Innovation and Transformation of Luobing Theory Key Laboratory of Cardiovascular Remodeling and Function ResearchChinese Ministry of EducationChinese National Health Commission and Chinese Academy of Medical SciencesDepartment of CardiologyQilu Hospital of Shandong UniversityJinanChina The Second Affiliated Hospital of Harbin Medical University HaerbinChina Peking University People's Hospital BeijingChina Sichuan Province People's Hospital ChengduChina Nanfang Hospital Southern Medical UniversityGuangzhouChina Peking Union Medical College Hospital Chinese Academy of Medical SciencesBeijingChina 不详

In the context of the People's Republic of China,coronary artery disease(CAD)presents a sig-nificant clinical challenge,with over 11.3 mil-lion patients ***,the diagnos-is of CAD has predominantly relied on invasive coronary angiography.[1]However,recent advances in clinical research have revealed a notable trend:a substantial 82% of patients subjected to such invas-ive diagnostics do not necessitate interventional therapy.

关键词： coronary clinical patients

Spectral characteristics of underwater laser-induced breakdown spectroscopy under high-pressure conditions

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2020年第7期22卷 28-35页

作者： Lintao WANG Ye TIAN Ying LI Yuan LU Jinjia GUO Wangquan YE Ronger ZHENG Optics and Optoelectronics Laboratory Ocean University of ChinaQingdao 266100People's Republic of China

Laser-induced breakdown spectroscopy(LIBS) has been proven to be an attractive technique for in situ oceanic ***,when applying LIBS into deep-sea,the pressure effect caused by different ocean depths is inescapable and could have great influence on the LIBS *** this work,spectral characteristics of underwater LIBS were investigated as a function of pressure in the range of 0.1-45 MPa.A high-pressure chamber built in the laboratory was used to simulate the high-pressure deep-sea *** laser energy and detection delay were first determined under different pressure conditions and were shown to be independent of the external *** increase in pressure has a significant impact both on the peak intensity and line broadening of the observed *** peak intensity of Na,Li and K lines increases with the increasing pressure until a maximum intensity is reached at 12.5 *** this value,the peak intensity decreases gradually up to 45 *** Ca line,the maximum intensity was observed at 30 *** line broadening keeps constant at low pressures from 0.1-10 MPa,while it increases linearly at higher pressures,indicating a higher electron density caused by the compression effect of the high external *** also compared the spectral data obtained from the high-pressure chamber and from the field sea trials,and the good consistency between the laboratory data and sea-trial data suggested the key role of pressure effect on underwater LIBS signals for practical deep-sea applications.

关键词： underwater laser-induced breakdown spectroscopy spectral characteristics high-pressure chamber pressure effect deep-sea application

Master crack types and typical acoustic emission characteristics during rock failure

在线全文

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2023年第1期10卷 73-86页

作者： Tongbin Zhao Pengfei Zhang Yaxun Xiao Weiyao Guo Yulong Zhang Xiufeng Zhang State key Laboratory of Mining Disaster Preventionand Control Co-founded By shandong Provinceand the Ministry of Science and Technology ShandongUniversity of Science and TechnologyQingdao 266590China College of Energy and Mining Engineering ShandongUniversity of Science and TechnologyQingdao 266590China State key Laboratory of Geomechanics and GeotechnicalEngineering Institute of Rock and Soil MechanicsChineseAcademy of SciencesWuhan 430071China research Center for Rock Burst Control Shandong EnergyGroup Co.Ltd.Jinan 250014China

Acoustic emission(AE)signals contain substantial information about the internal fracture characteristics of rocks and are useful for revealing the laws governing the release of energy stored *** here is the evolution of rock failure with diferent master crack types as investigated using Brazilian splitting tests(BSTs),direct shear tests(DSTs),and uniaxial compression tests(UCTs).The AE parameters and typical modes of each fracture type were obtained,and the energy release characteristics of each fracture mechanism were *** the observed changes in the AE parameters,the rock fracture process exhibits characteristics of staged *** scale and energy level of crack activity in the BSTs were signifcantly lower than those in the DSTs and *** proportion of tensile cracks in the BSTs was 65%–75%,while the proportions of shear cracks in the DSTs and UCTs were 75%–85%and 70%–75%,*** the rock loading process under diferent conditions,failure was accompanied by an increased number of shear *** amplitude,duration,and rise time of the AE signal from rock failure were larger when the failure was dominated by shear cracks rather than tensile ones,and most of the medium-and high-energy signals had medium to low *** calculating the proposed energy amplitude ratio,the energy release of shear cracks was found to exceed that of tensile cracks at the same fracture scale.

关键词： Rock failure Fracture mechanism Acoustic emission Master crack type Energy release